1. Field of the Invention
The present invention generally relates to dispensers and more particularly, to a dispensing head for use with a fluid product dispenser, wherein the fluid product dispenser dispenses fluid product in the form of a jet or a spray, and also to a fluid product dispenser having such a dispensing head.
2. Discussion of Background
Generally, a fluid product dispenser includes a reservoir containing the fluid product to be dispensed. The reservoir has an open end. A dispensing member, such as a pump or a valve, is fastened to the open end of the reservoir. A dispensing head is mounted on the dispensing member. The dispensing head performs two functions. First, the dispensing head allows the user to control the actuation of the dispensing member so that the dispensing member ejects a dose of fluid product from the reservoir. Second, the dispensing head makes it possible to convey the fluid product, leaving the reservoir, to a dispensing orifice, such as a nozzle, via an inlet conduit provided in the dispensing head. The dispensing of the fluid product is thereafter carried out either in the form of an approximately filiform jet, or else in the form of a cloud of fine droplets, often referred to as a spray. The fluid product may be conveyed to the dispensing orifice by simply pressing on a compressible product reservoir. When the fluid product dispenser is equipped with a dispensing valve, the reservoir contains a pressurized gas in addition to the fluid product. The pressurized gas is for propelling the fluid product to be dispensed through the dispensing orifice.
A conventional dispensing head, for dispensing a fluid product in the form of a jet or a spray, includes a body having an inlet conduit. The inlet conduit communicates with the product reservoir. The inlet conduit opens outwardly into a dispensing nozzle. The dispensing nozzle has an outlet orifice. The outlet orifice has a small cross section. Ordinarily, such a dispensing nozzle is an add-on piece which is non-detachably fixed to the dispensing head during manufacture.
If the dispensing head becomes blocked due to build up of product residues, it is practically impossible to unblock or clean the nozzle, and/or the inlet conduit, without damaging the dispensing head and without subsequent injury to the operation of the dispenser.
Blockage of the dispensing head may occur fairly frequently, when the fluid product is a solution or a dispersion which dries easily in the open air. Such fluid products are found among atomized glues, paints, and certain cosmetic or dermo-pharmaceutical products, such as hair and skin conditioning products, for instance, hair lacquers or sunscreen products.
U.S. Pat. No. 3,961,756 (xe2x80x9cthe ""756 patentxe2x80x9d) discloses a spray head comprising a nozzle screwed onto a free end of the fluid product inlet conduit. The ""756 patent teaches that the characteristics of the stream of fluid product or spray may be modified by rotation of the nozzle, which displaces the nozzle along the outlet axis of the fluid product jet. In the event of a blockage of the spray head, the nozzle may be dismantled in order to clean the spray head. However, it is still difficult to access the inlet conduits to unblock them when a blockage occurs. Further, once the nozzle is refitted after cleaning, numerous readjustment operations must be performed in order to ensure unchanged quality of spray. Furthermore, molding of the nozzle, to be screwed into the free end of the fluid product inlet conduit, is difficult or impossible. Thus, the nozzle must be made of metal and then must be machined. The metal and machining both raise the cost of manufacturing the nozzle. Finally, because the nozzle moves along the axis of the jet, it is vital, in order to prevent the nozzle from being expelled under the pressure of the jet, to ensure fastening by a screwing-type link.
A cleanable dispensing head for fluid products is described in WO-A-96/31 412 (xe2x80x9cthe ""412 referencexe2x80x9d). The dispensing head of the ""412 reference includes a fixed part and a detachable part. Thus, if the dispensing head of the ""412 reference becomes blocked, it is possible to access the dispensing orifice and the terminal part of the product inlet conduit, because the detachable part of the dispensing head is separable along a plane passing through the center of the dispensing orifice. If the dispensing orifice is of a particularly small size, a dispensing orifice in which the edge of the outline forms part of two different pieces is a major drawback. More particularly, when the dispensing head has a diameter generally between 0.1 mm and 1.0 mm and the dispensing head is made in two molded pieces, as is the case of the dispensing head of the ""412 reference, it is impossible to obtain an even edge for the dispensing orifice because of the presence of a sealing joint. Additionally, the presence of the sealing joint results in an uneven and coarse spray and makes it impossible to obtain an even spray cone with a fine and homogeneous size distribution of droplets.
European patent application publication no. 726 096 (xe2x80x9cthe ""096 referencexe2x80x9d) describes a spray head having a dispensing orifice which is movable with respect to an annular swirl chamber and to the conduits feeding the dispensing orifice with fluid product. The purpose of the spray head device of the ""096 reference is to vary the divergence characteristics of the spray obtained. The swirl chamber and conduits feeding the dispensing orifice with fluid product are not accessible for cleaning.
Other dispensing heads, such as those described in U.S. Pat. Nos. 2,989,251 and 3,319,894, French patent application publication no. 2 698854, and European patent application publication no. 0 790 079, are not dismantable or even temporarily openable for cleaning of the feed conduits therein.
Hence, one of the objectives of the present invention is to provide a dispensing head which is easily cleanable, without the requirement of complicated dismantling.
Yet another objective of the present invention is to provide a dispensing head which is easily refittable after cleaning.
Another objective of the present invention is to provide a dispensing head capable of ensuring the production of an even spray or jet having fine droplets of homogeneous distribution.
Yet another object of the present invention is to provide a dispensing head which is simple to manufacture, preferably by molding, so as to be fairly inexpensive.
The present invention relates to a dispensing head for use on a fluid product dispenser which dispenses a fluid product in the form of a jet or a spray. The dispensing head includes a body having an inlet conduit. The inlet conduit communicates with a stem of a pump or a valve of the fluid product dispenser. The dispensing head also includes a piece mounted on the body, wherein the piece has a dispensing orifice which can be detachably placed in communication with the inlet conduit.
In accordance with the present invention, the piece is movable at will, with respect to the body, in an X-direction different from a Y-direction, wherein the Y-direction is defined as the outlet direction of the jet or spray of the fluid product. The movement of the piece, with respect to the body, is for cleaning the inlet conduit. An advantage of the present invention is that the pressure exerted by the fluid product on the internal wall of the piece, which is movable and which surrounds the dispensing orifice, cannot modify the position of the dispensing orifice with respect to the body. Another advantage is that after repeated dismantlings and refittings of the dispensing head, the quality of the jet or spray of the fluid product is not impaired over time.
When the fluid product dispenser includes a valve, the fluid product can be conveyed to the valve via a pressurized propellant gas. The pressurized propellant gas may act directly or indirectly on the fluid product contained in a reservoir provided in the fluid product dispenser.
Advantageously, the inlet conduit, which is located opposite of the dispensing orifice, opens outwardly into a swirl chamber. Just before a stream of fluid product passes through the dispensing orifice, the swirl chamber is able to impart a convergent spiral acceleration motion to the stream of fluid product. The application of the convergent spiral acceleration motion to the stream of fluid product makes it possible to break-up the fluid product into particularly fine droplets, after the fluid product has passed through the dispensing orifice. The break-up of the fluid product into particularly fine droplets is especially useful in such cases as when using either a pre-compression pump or a dispensing valve, wherein the dispensing valve is used in combination with a compressed propellant gas which is insoluble in the fluid product.
According to a first embodiment of the present invention, the piece is movable, can be fully detachable, and at least partially shrouds the body. Preferably, the piece is placed in an appropriate position on the dispensing head or else, is dismantled from the dispensing head, via movement along a longitudinal axis which passes through the valve stem or pump stem. Thus, at least a portion of the inlet conduit is delimited, in part by the body and in part by the movable or detachable piece. In other words, a portion of the inlet conduit is defined by a volume delimited between an external surface of the body and an internal surface of the movable or detachable piece.
According to a second embodiment of the present invention, the dispensing orifice is situated on a plane portion of the movable or detachable piece. The plane portion delimits the swirl chamber and cooperates with a portion of the body in such a way as to position the movable or detachable piece at an angle with respect to the body. The portion of the body which cooperates with the plane portion of the piece is a xe2x80x9cflatxe2x80x9d. Thus, constant and reproducible quality of the spray is ensured, even after dismantling and refitting of the dispensing head.
According to a third embodiment of the present invention, the movable or detachable piece articulates with the body via a film hinge. Furthermore, the movable or detachable piece is pivotable. Thus, the dispensing head can be manufactured in a single piece through a single molding operation.
According to a fourth embodiment of the present invention, the movable or detachable piece can be a strip, which has been bent into an xe2x80x9cLxe2x80x9d shape. A free end of the xe2x80x9cLxe2x80x9d-shaped strip articulates with the body. The xe2x80x9cLxe2x80x9d-shaped strip includes an orifice on one of the two portions forming the xe2x80x9cLxe2x80x9d-shape. Thus, the movable or detachable piece includes two portions. A first portion of the two portions of the movable or detachable piece has the orifice therein. The first portion also has a free end adjacent to the film hinge. A second portion of the two portions of the movable or detachable piece is in leaktight contact with the upper part of the body. Together, the second portion and the body delimit a part of the inlet conduit. Furthermore, the movable or detachable piece may have a snap-fit means for snap-fittingly cooperating with complementary snap-fit means carried on the body. Thus, the movable or detachable piece may be immobilized during the actuation of the dispensing head.
Advantageously, the dispensing head of the present invention has a push-button with a bearing surface. A user of the dispensing head pushes on the bearing surface of the push-button to eject a dose of fluid product.
The present invention also relates to a dispenser, wherein the dispenser includes a reservoir of fluid product. A pump or a valve is mounted on the reservoir and the reservoir is equipped with a dispensing head as has been defined above.